kelly, You want to keep your orignal windows, but the sound and energy performance leaves much to be desired. As Guy mentioned earlier, your best option for sound control is laminated glass. And, in addition to sound attenuation, laminated glass cuts out 99% of UV light from getting into your home...it even (potentially) offers greater security as well. This is what soundproof window's (and others) offer - often with an amazingly inflated price tag. The wide airspace between the layers of glass (original windows to add-on sound control glass) will offer sound advantages as well. Again, soundproof window's uses this to their advantage as well - especially when installing an interior storm window. Okay, the best of both worlds... Contact a local handyman (a good one) and have him construct wood storm sashes out of whatever wood/finish that you desire. Next, fill those frames with 1/4 laminated glass as Guy suggested. Make sure that the storms are installed tight using a good quality weatherstrip. You have now increased both energy performance and -especially - sound perfomance of your existing windows. Hopefully at a price significantly less than what you would pay one of the "sound specialist" companies. And you have kept the look and feel of the existing windows. The primary drawback is that you will lose your ability to open the original windows for fresh air - depending on how the storms are designed and mounted. But, if too much noise from outside is the significant issue, then I would suspect that opening the windows is not a primary consideration.

Thanks to everyone for their thoughts. The Nanas we're putting in are going to be a Medium Bronze. That gives us some flexibility because I believe that most companies that produce aluminum windows will do a similar color. Good point on the thermally broken feature. I forgot to add that was also on our short list. We had not considered fiberglass and will look that up now. Does anyone know of a brand that we should check for either material? There are so many manufacturers that it's hard to know where to start.

Milgard and Fleetwood are both good to look at. Another is Blomberg. It is a smallish family run company near Sacramento. No web site. Call them and they will send a nice packet. Beautiful product. Cost-wise, it goes Milgard (lowest) - Fleetwood (mid) - Blomberg (highest). Blomberg is maybe 2x Milgard. Both Milgard and Fleetwood offer 'thermally broken' frames. But strangely, the Milgards are not available in California... So if that is an issue for you, Fleetwood may be a better choice. We went through this last spring. A nice thing about aluminum frames is that they are thin by comparison to other styles. So they look better in modern/contemporary designs. This is probably why your architect is steering you towards them. Ours did too. In the end we chose Milgard, and are very happy with them. Got the dark bronze frames - which look very cool. Also got the Solar Max glass. We have a mix of casements, and sliders. Also two sliding doors - with fixed windows above them. (Vaulted ceilings.)

Xena99, Contrary to what some people think, it's not the temperatures that are destroying your window frames, it's UV degradation - the bane of ALL plastics. Any plastic (pvc & fiberglass included) can be made more resistant to UV damage by simply painting it. When it comes to windows, you can install all of the hi-performance windows that you want, but my money will always be bet on storm windows - simply because they work. You can tint them or do whatever you want to them without hurting your new windows or their warranty. As a matter of fact, when properly installed they will actually extend the life of your new windows and the money you save on your heating/cooling costs will pay for the storm windows long before they wear out. Many articles have been written regarding the poor pay-back that results from hi-performance windows vs. added up front costs and the glass failures that only make the pay-back figures even worse. Here is a link that might be useful: Storm Windows